Color Code Calendar By Category

Hi All,

I am fully aware of the calendar overlay but do not want to use it. I am going to have two Categories (A or B)

I want A to to have a background color of green, and B have Blue.

I have tried several times with calculated columns, and adding java to a content editor but nothing seems to work right!

Can someone help me, this is one example of code i tried.

="<div style='width:100%;background-color:"&IF(Category="Meeting","Red",IF
(Category="Business","Blue",""))&";'> "&Title&"</div>"

This seems so easy on tutorials but i cant get anything to work! simply just want it to be if category = a then background color is green...etc

this is an easy answer for someone, I will mark as answer.